When In Treatmentreturns for a sophomore season next year, Dr. Paul Weston will find himself dealing with some new faces. As mentioned back in October, Hope Davis (Six Degrees, Deadline) and John Mahoney (Frasier) will be joining the Emmy Award-winning HBO drama respectively as a high-powered malpractice lawyer and former patient of Weston's who blames him for being single and childless, and a self-confident CEO who feels that his life is getting away from him. But that's not all.

According to Zap2it.com, In Treatment has also booked Lincoln Heights' Russell Hornsby as one of Dr. Weston' new regular patients. On the series, Hornsby will play a divorced guy with a 12-year-old son.

Russell Hornsby is credited for his roles on Playmakers, Haunted and Gideon's Crossing, though he is best known for portraying Los Angeles Police Department officer Eddie Sutton on the acclaimed ABC drama Lincoln Heights.

Aside from Hornsby, Alison Pill will also join the cast of In Treatment as a patient with lymphoma. No further details have been revealed about her character so fans will just have to stay tuned when the show returns with new episodes next year. Pill is noted for her role as Grace Webster in the short-lived NBC drama The Book of Daniel, and was nominated for a Tony Award for her performance in Martin McDonagh's The Lieutenant of Inishmore.

Premiered on January 28 as a five-night-a-week serial drama, In Treatment takes viewers inside the mind of a man who counsels others for a living. Though ratings have been mediocre, the critical reception towards the show has been mostly positive, thus earning a second season order, with only cast members Gabriel Byrne (Paul) and Dianne Wiest (Gina) confirmed to return.

According to HBO, the series has already started production for second season in New York.